The present invention is directed generally to tape measures (or “tape rules”) of the type commonly used to measure linear distances. Conventionally, these devices include a flexible tape blade, with distance markings thereon, that can be extended from a housing to measure linear distances. Generally, the tape blade in these devices is constantly subjected to a retraction bias (e.g., from a retraction spring) for pulling the tape blade back into the housing. As such, modern tape measures typically incorporate some type of locking feature to selectively hold the blade in an extended position. Typically, these features require positive engagement in that they are actuated after the tape blade is extended. In other types of tape measures, the locking feature is automatic. That is, once the tape blade is pulled out to an extended position, the tape blade automatically remains in that position until a release mechanism is actuated to allow the return spring to pull the tape blade back into the housing. These latter types of tape measures are sometimes referred to as “auto-lock” tape measures.
Conventional auto-lock tape measure designs often use a locking mechanism that pinches the tape blade at or near the opening where the tape blade exits the housing. However a pinching force applied to the tape blade imparts friction and undesirable wear on the tape blade. Further, the tape blade is a flexible member and may not provide an optimal braking surface on which to apply a locking force. In addition, the interior of the housing adjacent to the tape blade opening, and thus the locking mechanism, may be susceptible to dirt or foreign object contamination. Accordingly, conventional auto-lock designs may not be ideal in all circumstances. As such, there remains a need for alternative auto-lock locking mechanism designs; advantageously, designs that provide robust and consistent locking forces over extended use.